Permanent magnet (PM) actuated microrobotics offers significant advantages for minimally invasive medicine, but faces three critical challenges: nonlinear magnetic force relationships, directional control asymmetry between horizontal and vertical motion, and imaging–capturing frequency mismatch. This letter presents a hierarchical control framework enabling precise 3D manipulation of magnetic beads using a single PM. Our approach addresses these challenges through: (1) a decoupled XY-Z control architecture that independently handles horizontal damped dynamics and vertical unstable equilibrium, (2) feedback linearization that transforms nonlinear magnetic forces into linearly controllable systems, and (3) predictive feedforward compensation that bridges the 120 ms imaging interval with 10 ms actuation requirements. Experimental validation demonstrates sub-millimeter positioning accuracy (maximum oscillations: 0.210 mm in the Z-direction, 0.013 mm in the XY-plane) across diverse environments, including free liquid space, narrow maze channels, and tubular structures. The system successfully navigates complex 3D trajectories while maintaining contactless control, achieving 60%–80% cost reduction compared with electromagnetic alternatives. Applications include targeted drug delivery, minimally invasive diagnostics, and precise tissue manipulation in constrained anatomical environments.

The motion of magnetic microrobots relies on an external magnetic field. Current electromagnetic propulsion systems are often complex in structural design, challenging in control strategies, and associated with high energy consumption. In this study, we introduce a mechano-electromagnetic hybrid actuation system that employs only a pair of Helmholtz coils to generate an oscillating uniform magnetic field, combined with a rotating platform to modify the field’s direction, thereby enabling the control of microrobot speed and direction. The properties of this hybrid actuation system were modeled and validated to analyze the magnetic field distribution within the workspace. The design and actuation of two microrobots are described in detail. Furthermore, a visual feedback closed-loop control strategy for the system was developed. A series of navigation control experiments were conducted, demonstrating that the proposed hybrid actuation system achieves effective microrobot actuation and precise control while reducing manufacturing costs and simplifying control strategies. The proposed novel mechano-electromagnetic hybrid structure contributes to the field of electromagnetically driven systems and magnetically controlled microrobots.

Oxide thin-film transistors (TFTs) with high mobility and excellent stability are extremely desired for advanced displays. In this work, we simultaneously enhanced the mobility and stability of In2O3 TFTs by nitrogen modification strategy, and systematically investigated the effects of nitrogen doping content on the structures and properties of In2O3 films and the TFT performance. With increasing amount of the nitrogen flow rate from 0 to 9 SCCM, crystallinity and surface quality are improved, while the oxygen defect, optical bandgap, and Urbach energy are decreased, gradually. At a suitable nitrogen flow rate of 6 SCCM, In2O3 films exhibit optimal comprehensive properties, such as high crystallinity, low surface roughness, and defect density, yielding significant enhancement in TFT performance. In particular, the N modified In2O3 TFT demonstrates a highest mobility of 24.96 cm2/V s, accompanied by superior positive and negative bias stability. And then, degradation mechanisms of the TFT stabilities are comprehensively revealed. The findings may be generalizable to other oxide electronics.

Miniature underwater robots play a crucial role in the exploration and development of marine resources, particularly in confined spaces and high-pressure deep-sea environments. This study presents the design, optimization, and performance of a miniature robotic fish, powered by the oscillation of bio-inspired fins. These fins feature a rigid-flexible hybrid structure and use an eccentric rotating mass (ERM) vibration motor as the excitation source to generate high-frequency unidirectional oscillations that induce acoustic streaming for propulsion. The drive mechanism, powered by miniature ERM vibration motors, eliminates the need for complex mechanical drive systems, enabling complete isolation of the entire drive system from the external environment and facilitating the miniaturization of the robotic fish. A compact, untethered robotic fish, measuring 85 × 60 × 45 mm3;, is equipped with three bio-inspired fins located at the pectoral and caudal positions. Experimental results demonstrate that the robotic fish achieves a maximum forward swimming speed of 1.36 body lengths (BL) per second powered by all fins and minimum turning radius of 0.6 BL when powered by a single fin. In addition, the robotic fish is able to swim upstream in turbulent flow, and its autonomous version can navigate complex, obstacle-filled environments. These results underscore the significance of employing the ERM vibration motor in advancing the development of highly maneuverable, miniature untethered underwater robots for various marine exploration tasks.

High-temperature thin-film thermocouples (TFTCs) have gained significant attention in the aerospace and energy industries due to their compact size and millisecond response time. Although previous studies have reduced the size of TFTCs to the millimeter scale, the heat flow field has continued to limit temperature measurement accuracy. To address this issue, this study used an electrohydrodynamic printing process to fabricate tungsten-rhenium TFTCs with a thickness at the micrometer scale. In the static test, the tungsten-rhenium TFTCs showed good performance with a measurement accuracy better than 1.2%, repeatability better than 0.99%, and a drift rate of 0.72%/h. In dynamic tests, the response time was 1.2 ms. Additionally, during flame gun heating tests, the response time and temperature measurement accuracy exceeded those of the standard thermocouple.